1. Field of the Invention
The present invention relates to improved structure for high resolution mouse, in particular, to a mouse equipped with a frictional sleeve on each one of two pairs of transmission shafts with wheel circumferential length multiple of that of corresponding sleeve so as to increase rotational ratio and fasilitate an associated pair of infrared detectors able to detect bright/dark intermittent variation of light input more distinctly and reliably from a pair of light shading wheels in a given time duration and deliver corresponding high resolution (Dot Per Inch, DPI) signals.
2. Description of the Prior Art
Among variety of mice usable for computers, the mechanical type is mostly welcome for its reliability and low price. But there is a problem that resolution (Dot Per Inch, DPI) is poor due to difficulty in its mold design and manufacturing. As a result, in order to improve DPI of a mouse, most of the manufacturers think it is better to invest in manufacturing high DPI yet costy photoactive mice without consideration of user""s financial burden.
Meanwhile, in a conventional castor equipped mechanical mouse shown in FIG. 4 wherein a frictional rubber castor is equipped to roll on a table or a mouse mat thereby driving an infrare ray shading wheel in a housing of the mouse with 1:1 transmission ratio between the castor and the shading wheel. By so, the castor has to travel a considerably long distance before it reaches the desired spot. Such is not only inconvenient to the operator, but also degrades the sensibity and shortening the life time of a mouse for the reason that the mouse may possibly be accumulating dust on its castor during a long journey.
In order to solve the above depicted problems, the present inventor has carried out theoretical studies and simulating experiments for a long time efforts. Based on these studies and researches, the present inventor came to propose the present invention.
Therefore, it is an object of the present invention to provide a high resolution mouse which is equipped with a frictional sleeve on each one of a pair of transmission shafts with transmission wheel circumferential length multiple of that of corresponding selves so as to increase rotational ratio and fasilitate an associated pair of infrared detectors able to detect bright/dark intermittent variation of light input more distinctly and reliably from a pair of light shading wheels in a given time duration and send out corresponding high resolution (DPT) signals.
It is another object of the present inventional to provide a high resolution mouse whose rotational ratio between the transmission wheel and the frictional sleeve is adjustable according to desired resolution.
It is a further object of the present invention to provide a high resolution mouse whose small distance of displacement is equivalent to a large step displacement made by a conventional mechanical mouse so as to eliminate the disadvantageous accumulation of dust on the castor and prolong lifetime of the mouse.
It is still further object of the present invention to provide a high resolution mouse with a low production cost and cheap market prices as well.
To achieve these and other objects, the high resolution mouse of the present invention comprises a spherical castor; a first transmission wheel unit including a transmission wheel whose rotating shaft is equipped with a first frictional sleeve at a proper position thereof; a second transmission wheel unit including a transmission wheel whose rotating shaft is equipped with a first frictional sleeve at a proper position thereof; a light shading wheel whose rotating shaft is equipped with a second frictional sleeve at a proper position thereof; a light shading wheel whose rotating shaft is equipped with a second frictional sleeve at a proper position thereof; several supporting posts for sustaining the first and the second transmission wheel units; and two infrared sensors.
With the above structure the spherical castor is in contact with the first frictional sleeves of the first and the second transmission wheel units, the transmission wheel of the first transmission wheel unit is in contact with the second frictional sleeve of the first transmission wheel unit, and the transmission wheel of the second transmission wheel unit is in contact with the second frictional sleeve of the second transmission wheel unit. Each of the two infrared sensors is respectively disposed abut on each of the light shading wheels belonging to the first and second transmission wheel units respectively for detecting bright/dark change of light and delivering corresponding DPI signals.
In the present invention, all the frictional sleeves are of cylindrical shape, and the circumferential length of the transmission wheels is multiple of that of corresponding sleeves, and the ratio is variable so as to improve resolution of the mouse to any desired degree.
In the present invention, the fringes of both transmission wheels are serrated so as to stabilize rotation of the transmission wheels.